Researchers from University College Cork, in Ireland, have conducted a meta-analysis of the evidence linking probiotics (see Probiotics Learning Lab) and their potential for helping to support health in those with psychiatric illnesses, such as depression. They found that there could be great potential for probiotics to exert a marked health benefit to those suffering with mental health issues, and coined the term 'psychobiotics' in their article featured in Biological Psychiatry.
The gut-brain axis, has been a hotbed of recent scientific research
The link between the gastro-intestinal tract and mental wellbeing, typically referred to as the gut-brain axis, has been a hotbed of recent scientific research. One such study, in lab rats, focused on the stress induced by maternal separation. The study found that the probiotic supplementation of Bifidobacterium infantis normalised the behaviour of rats showing symptoms of depression, and also altered any abnormalities in immune function. Other reviewed studies concluded that some probiotics have an anti-inflammatory effect, which is significant as inflammation is closely associated to psychiatric illnesses. The authors commented, "the intestinal microbial balance may alter the regulation of inflammatory responses and in so doing, may be involved in the modulation of mood and behaviour."
Human clinical trials have also shown positive results. Of particular note is a study conducted using the supplementation of Bifidobacterium longum and Lactobacillus helveticus R0052, also known as L. acidophilus Rosell-52. This study revealed that volunteers reported much lower stress levels than those receiving placebo.
Another similar study showed that probiotic yoghurt also improved mood and decreased stress levels24. The small study, published in the peer-reviewed journal Gastroenterology, divided 36 women into three groups; one ate a probiotic yoghurt containing species of both the Bifidobacterium and Lactobacillus families of bacteria (Bifidobacterium animalis subsp Lactis, Streptococcus thermophiles, Lactobacillus bulgaricus, and Lactococcus lactis subsp Lactis) twice a day for four weeks, the second group ate a non-probiotic dairy product with a similar look and taste, and the other group had no product at all. Scans (functional magnetic resonance imaging) were taken before and after the four week long study, and the participants' brains were scanned both during a period of rest, and also during an emotion-recognition task, where women were asked to match pictures of people with angry or frightened faces to other pictures demonstrating the same emotions.
The women who had been taking probiotics showed altered brain activity in regions of the brain which are known to process not only emotions, but also sensations. What's interesting in particular is that researchers from UCLA were surprised to see effects in the brain occurring not only in the areas associated with emotions, but also those involved in sensory processing.
Mental health during pregnancy
Depression globally affects more than 264 million people of all ages. Statistically it affects more women than men. Whether they have had a history of mental health issues or not, pregnant women may be concerned about whether depression is common in pregnancy. In fact, as many as 1 in 5 women have mental health problems in pregnancy or after birth. Depression and anxiety are the most common mental health problems in pregnancy3. Depression in pregnancy may diminish one’s capacity for self-care at this critical time. This may have a knock-on effect on a mother’s overall nutrition status, and even cause an increase in drug and alcohol abuse or a reduction in antenatal clinic attendance. All these factors may compromise a woman’s physical health and may restrict the growth and development of the unborn child4.
A few days after giving birth, it is common to experience a period of low mood known as the ‘baby blues’. This affects 30 to 80% of women, and is thought to be due to a 100 fold drop in oestrogen levels which occurs at this time and for up to 10 days after birth5. This can make the mother anxious, tearful, irrational, and irritable. These feelings generally subside after 14 days but for some women they may persist. The weeks and months following childbirth may be a time of extreme exhaustion due to lack of sleep but continuing low mood after giving birth should be discussed with a doctor, as it is possible that the mother may have developed postnatal depression.
Postnatal depression has very similar symptoms as general depression. Previous depression, current depression/anxiety, and low partner support are found to be key antenatal risk factors for postnatal depression6. It has been suggested that 33% of postnatal depression begins in pregnancy and 27% in pre-pregnancy7.
Hormones tend to get much of the blame when it comes to mood swings and the emotional rollercoaster of pregnancy. Each woman’s experience is different, so it can be difficult to know what is normal in terms of fluctuating moods. There is no consistent evidence that women who develop depression during pregnancy experience lower reproductive hormone concentrations, or experience greater reductions in hormone levels. However, there is evidence9 to suggest that hormone fluctuations can trigger dysregulation in sensitive women. It is likely that these hormone fluctuations can cause changes within the body and therefore affect the hypothalamic-pituitary-adrenal (HPA) axis (involved in the body’s response to stress), amongst other areas.
Certain hormones in particular have been identified as playing a part in mood. Oestrogen, involved in baby’s early development, has been shown to increase the number of serotonin (happy hormone) receptors while enhancing its transport and uptake into the cells10. It is also interesting to note that the onset of depression in women is often at times when oestrogen levels are relatively low (in early pregnancy, postpartum, and around and following menopause)11. Reduced release of oxytocin (involved in breastmilk production and bonding between mother & baby) has also been associated with depression in mothers. It is understood that disruptions of the oxytocin system may be implicated in relations between breastfeeding, stress regulation, and mood. These are all affected areas during postnatal depression.
Whilst hormones can be troublesome, they do play a vital role in a healthy pregnancy and baby. The key is to keep them in balance and supporting gut health is one way of doing this.
Mums dealing with depression in pregnancy should always consult with a doctor. The best treatment is very individual to the mother and both medication and psychological therapies can help18. Antidepressants are commonly prescribed to help manage symptoms; however these may not be suitable during pregnancy or breast-feeding. In some cases, GPs may recommend talk therapies as an alternative; Cognitive Behavioural Therapy (CBT) and counselling have helped many.
As pregnant mums are often reluctant to take prescriptions at this special time, there is a growing interest in natural lifestyle interventions. Probiotics are becoming well-known as part of a natural mental health support protocol, with certain strains such as Lactobacillus acidophilus Rosell-52 showing real promise for anxiety symptoms.
Probiotics are very safe to take during pregnancy and breastfeeding, but certain strains have been specifically researched in pregnant women, and of particular interest here are those strains which have been researched for the support of mental health during and after pregnancy. Lactobacillus rhamnosus HN001 has been used in gold standard clinical research and showed extremely encouraging results. In the trial of 380 women, this probiotic strain was used successfully for postnatal depression and anxiety19.
Probiotics protect against heavy metals
Heavy metals are a natural component of the earth and are therefore found in the soil, water, and can be airborne too. They are natural metals but are toxic in the body in even tiny quantities. Commonly known heavy metals are mercury, lead, cadmium and aluminium. These are not to be confused with trace elements such like zinc, iron, copper, and magnesium which are also metals but are necessary for the correct function of the body (although even with these problems occur when you have too much of them in your body).
Scientists are learning a lot more about what happens to the human body when even low exposure to heavy metals takes place over a length of time. When they become toxic in our body, heavy metals accumulate and can affect our brain, internal organs and development. They are also known to cause defects in babies in vitro. More commonly known effects of toxic levels of heavy metals are age related bone loss, memory loss and energy production issues, joint issues, anaemia, and even Alzheimer’s.
A fascinating study published in the Journal of the American Society of Microbiology suggests that including a yoghurt containing a probiotic can protect children and pregnant mothers from heavy metal poisoning25.
A research team from the Canadian Centre for Human Microbiome and Probiotics ran a study based in Mwanza, Tanzania. Mwanza is located on the shores of Lake Victoria and is known to be heavily polluted with pesticides and toxic metals that include mercury; additionally fish drawn from the lake full of these toxic metals are one of the main sources of food for this population. It follows that this society is at a high risk of heavy metal poisoning.
Two populations considered at exceptionally high risk, children under the age of five and pregnant women were studied. 44 children were followed over 25 days and 60 pregnant women were followed in their last two trimesters. These groups were found to have an elevated mercury and lead level compared to age and sex matched Canadians. Both groups were given a yoghurt containing the probiotic strain Lactobacillus rhamnosus GR-1®, while control groups were not given any. Changes in blood metal levels and the children’s gut microbiome were assessed. During the lab research it was noticed that this bacteria strain L. rhamnosus GR-1® had a tendency to bind with toxic heavy metals. Therefore the team led by Dr. Gregor Reid hypothesized that regular intake of this probiotic strain can prevent the metals from being absorbed from the diet.
A significant protective effect of the probiotic was found against mercury and arsenic in pregnant women suggesting that including yoghurt containing L. rhamnosus GR-1® in ones diet successfully protects pregnant women and possibly children against heavy metal poisoning. This is important as a reduction in these compounds lowers the risk of negative developmental effects in the foetus and newborns.
Support groups for Mental Health
There are some fantastic support groups and resources throughout the UK that focus on mental health and wellbeing. These include:
Best beginnings
MIND
Probiotics can help with depression, says new study
New study confirms a role for the gut bacteria in depression
